<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<body>
		<script>
			var year=prompt("请输入年份");
			if(year<=0){alert("年份错误！！");}
			else if(year%4==0&&year%100!==0||year%400==0){
				alert("闰年");
			}else{
				alert("不是闰年");
			}
		</script>
	</body>
</html>
